Walking on water is a way of life for some aquatic insects such as water striders. The tiny hairs on their long legs provide both a hydrophobic (water-repellent) surface as well as a large surface area to spread their weight across as they scoot over ponds, lakes and other waterways at mind-boggling speeds.

This remarkable ability has now been replicated in machine insects. Chinese scientists report that they've developed an aquatic microrobot that mimics the water-walking abilities of water striders.

Credit: American Chemical Society

The robot insect is faster, more agile and cheaper to fabricate compared to previous designs, making it a prime candidate for military spy missions, water pollution/supply monitoring, and other applications, the scientists say.

The robot has a body about the size of a quarter and is outfitted with ten superhydrophobic wire legs, and two movable, oar-like legs that are propelled by two miniature DC motors.

According to a study appearing in the journal, ACS Applied Materials & Interfaces, "The microrobot could not only stand effortlessly but also walk and turn freely on the water surface, exhibiting an interesting motion characteristic." View the video (.avi).

"Because the weight of the microrobot is equal to that of about 390 water striders, one might expect that it will sink quickly when placed on the water surface," the report noted. Instead, the mechanical creature stands effortlessly on water surfaces and also walks and turns freely.